Articulated couplings on a shared bogey comprise a soleplate associated with one of the vehicles, supported by the shared bogey via springs, and carrying a ball member via elastomer members, with the top surface of the ball member supporting a socket bearing surface that is associated with the other vehicle.
Such articulated couplings comprising spherical surfaces require a great deal of machining.
In addition, they are expensive and relatively heavy.
Document EP-A-0 279 245 in the name of the Applicant describes a device for linking together two rail vehicles that allows the bodies of the vehicles to rotate relative to each other about both a vertical axis and a horizontal axis, which device also defines a gangway compartment interconnecting the two bodies, the compartment comprising two elements that are interconnected by a flexible link, each element being hinged relative to the adjacent body about a vertical axis in common therewith.
The link device described does not include a carrying bogey, and the hinge between each of its elements and the corresponding body is provided by a high-position ball and a convex sector at the end of the body sliding inside a concave sector at the end of the element.
Documents DE-A-1 094 289 and U.S. Pat. No. 3,667,820, and more particularly document EP-A-0 343 482 in the name of the Applicant, describe an articulated coupling for two rail vehicles supported on a shared bogey between the two rail vehicles and comprising:
a toroidal part connected to one of the vehicles having a frustoconical surface in its lower portion and a cylindrical surface in its upper portion, thereby defining first and second cylindrical outside surfaces, and including a cylindrical bore in its center; PA1 a support part connected to the other vehicle, including in its upper portion first and second inside cylindrical portions respectively facing said cylindrical outside surfaces of the upper portion of said toroidal part and surrounding said toroidal part by means of a soleplate situated at a level below said toroidal part; PA1 a cylindrical pivot fixed on said soleplate and engaged in said cylindrical bore; and PA1 a toroidal coupling element fixed on said soleplate and providing articulated coupling between said soleplate and said toroidal part. PA1 a toroidal part connected to one of the vehicles A, having a frustoconical surface in its lower portion, and a cylindrical surface in its upper portion, thereby defining first and second cylindrical outside surfaces, and including a cylindrical bore in its center; PA1 a support part connected to the other vehicle B, including an inside cylindrical portion in its upper portion facing said cylindrical outside surface of the upper portion of said toroidal part and surrounding said toroidal part by means of a soleplate situated at a level below the level of said toroidal part; PA1 a cylindrical pivot fixed on said soleplate and engaged in said cylindrical bore; PA1 a toroidal coupling element fixed on said soleplate and providing articulated coupling between said soleplate and said toroidal part; PA1 energy absorption means disposed between the first or second cylindrical outside surfaces of said toroidal part and the surface of said vehicle A or B facing said first or second outside surface; and PA1 shear means holding said support part to longitudinal translation means fixed to said support arm connected to said other vehicle B. PA1 the energy absorption means are disposed between said second cylindrical outside surface of the upper portion of said toroidal part and said facing surface of said other vehicle B; PA1 at least one energy absorption means is disposed between at least one outside surface of the upper portion of the toroidal part and a respective one of the facing surfaces of vehicle A; PA1 the energy absorption means are constituted by a sheet metal structure made of a material selected from: ordinary steel; stainless steel; an aluminum alloy; and a combination of said steels and/or alloys; PA1 the energy absorption means are honeycomb structures made of a material selected from: ordinary steel, stainless steel, an aluminum alloy, and combination of said steels and/or alloys; PA1 the energy absorption means are spring type elements combining rubber and metal; PA1 the energy absorption means comprise a succession of structures of progressively differing stiffnesses; PA1 the energy absorption means are made of a visco-elastic material received inside cavities made of a material selected from: ordinary steel, stainless steel, and aluminum alloy; PA1 the shear means are made of safety bolts, with the number of bolts depending on the force to be absorbed, and serving to prevent longitudinal translation of the support part along the support arm; PA1 the shear means include lines of weakness; PA1 the longitudinal translation means are constituted by means selected from: rails, rolling paths, and slideways; and PA1 the longitudinal translation means include, at one end, means for limiting the stroke of the support part along the support arm and preventing the bodies of the vehicles from separating while the train is being pulled after the shear means have sheared. PA1 a toroidal coupling element absorbs the energy induced by the forces caused by normal traction or braking of the train; PA1 the toroidal coupling element and energy absorption means absorb the energy induced by forces due to minor shocks caused by trains being coupled together at speeds slightly in excess of an authorized speed; and PA1 the toroidal coupling element and the energy absorption means absorb the energy induced by forces due to violent shocks caused by minor collisions or by trains being coupled together at unauthorized speeds without damaging the toroidal coupling element because the shear means co-operating with the longitudinal translation means are sheared.
The articulated couplings for two rail vehicles described in the prior art documents do not make it possible to maintain mechanical links between the bodies of the rail vehicles and the structures of the vehicles while also absorbing energy in the event of minor collisions.
The articulated couplings for two rail vehicles described in the prior art documents have the drawback of being rigid and therefore of suffering damage in the event of minor collisions.